Genetic relationships of Japanese and Korean bagrid catfishes inferred from mitochondrial DNA analysis

Abstract

Partial sequences of the cytochrome b gene (740 bp) and restriction fragment length polymorphisms in the mitochondrial DNA were used to examine inter-and intraspecific relationships among nine species of bagrid catfishes (family Bagridae) in Japan and Korea. Several opinions have been expressed regarding the kinship among Japanese and Korean bagrid catfishes, based on external morphological similarities. Almost all of them, however, were rejected by the current data sets. For instance, it has been considered that the Korean species, Pseudobagrus brevicorpus and P. fulvidraco, were closely-related to P. ichikawai and P. nudiceps, respectively, found in Japan. Resulting trees indicated that P. ichikawaibranched off separately from all of the remaining Pseudobagrus species. Similarly, P. nudiceps and P. fulvidraco were represented by distantly separated branches. The intraspecific genetic divergence of bagrid catfishes was relatively small, even among geographically distant populations.